Generally a hearing aid system according to the invention is understood as meaning any device which provides an output signal that can be perceived as an acoustic signal by a user or contributes to providing such an output signal, and which has means which are customized to compensate for an individual hearing loss of the user or contribute to compensating for the hearing loss of the user. They are, in particular, hearing aids which can be worn on the body or by the ear, in particular on or in the ear, and can be fully or partially implanted. However, those devices whose main aim is not to compensate for a hearing loss but which have, however, measures for compensating for an individual hearing loss are also concomitantly included, for example consumer electronic devices (televisions, hi-fi systems, mobile phones, MP3 players etc.).
Within the present context a traditional hearing aid can be understood as a small, battery-powered, microelectronic device designed to be worn behind or in the human ear by a hearing-impaired user. Prior to use, the hearing aid is adjusted by a hearing aid fitter according to a prescription. The prescription is based on a hearing test, resulting in a so-called audiogram, of the performance of the hearing-impaired user's unaided hearing. The prescription is developed to reach a setting where the hearing aid will alleviate a hearing loss by amplifying sound at frequencies in those parts of the audible frequency range where the user suffers a hearing deficit. A hearing aid comprises one or more microphones, a battery, a microelectronic circuit comprising a signal processor, and an acoustic output transducer. The signal processor is preferably a digital signal processor. The hearing aid is enclosed in a casing suitable for fitting behind or in a human ear.
A traditional hearing aid system may comprise hearing aids for both the left and right ear and in that case be denoted a binaural hearing aid system. However as discussed above a hearing aid system needs not be binaural.
In the context of the present disclosure, an enriched sound should be understood as a sound having a quality whereby it is easy to relax and be relieved of e.g. stress and anxiety when subjected to it. The sounds of nature are one example of enriched sound.
It has been suggested within the art of tinnitus alleviation to use enriched sound as a means of disguising silence, whereby the brain's attention may be diverted away from the silence and hereby away from the tinnitus. Additionally, people suffering from tinnitus may benefit from enriched sound since this can lessen the perceived contrast between the tinnitus and the sound environment.
Tinnitus Retraining Therapy (TRT) is another method that has been used to try to alleviate tinnitus. TRT methods generally use white noise provided to the tinnitus patient at a level below the tinnitus.
EP-B1-2132957 discloses a sound enrichment system for the provision of tinnitus relief, wherein a noise signal is random or pseudo-random modulated whereby the monotony of the noise signal is reduced and the resulting sound made more comfortable to listen to for many users. Random modulation of the amplitude and the frequency characteristics of the noise signal are disclosed.
One problem with this system is that despite the fact that the monotony of the noise signal is reduced, many users may still find the sounds uncomfortable to listen to. This may especially be the case for the prolonged time of use required by most TRT methods.
U.S. Pat. No. 6,816,599 B2 discloses one type of enriched sound that can be generated by a music synthesizer in a way that is very well suited for implementation in e.g. a hearing aid.
It is a feature of the present invention to provide a method for the generation of enriched sound with improved listening comfort.
It is another feature of the present invention to provide a hearing aid and a hearing aid system adapted to provide enriched sound with improved listening comfort.
It is yet another feature of the present invention to provide enriched sound that has a broad frequency spectrum and is comfortable to listen to.